When subsurface wellbores are drilled, such as for oil or natural gas production, the drilling operation typically generates cuttings that must be removed. To remove those cuttings fluid substances known as “drilling mud” may be circulated through the various parts inside the wellbore, including casing and various parts of the drill string including drill pipe and any subassembly and the drill bit. As used herein, the term “fluid” shall broadly mean any liquid or liquid-like material that is circulated through the wellbore, including not only water but also drilling mud (which includes various chemicals and materials designed to add “weight” to the drilling mud) and any solids, including cuttings and sand.
In the past, a variety of approaches have been used to facilitate drilling operations. Many of those approaches, including various types of grooved drill collars, are described in various prior art publications or patents, including those listed on the face of the patent. While certain of those approaches are purported to have advantages or benefits for specific applications, the inventors perceive that they also have shortcomings, and that a need exists for the devices, methods, and systems described herein.